Ok, so I know I need a refractometer...

[jsbradbury]

...but is there any way I can tell how accurate my hydrometer is? I tested my water today at two different temps. At 76 degrees I got a reading of 1.0205 and at 84 degrees it read 1.024. Next paycheck I will be buying a refractometer, but untill then is there any way to figure this out? Is the hydrometer calibrated for a certain temp?

 

[Simon1]

Most hydrometers are calibrated for 60 F .

 

[EmilyB]

Is it a floating hydrometer? If so, it is not temp corrected.

A float arm like seat test is temp corrected, but not always accurate. I measure my float arms to my refract for easier measurements in the tanks. One reads exact and one reads two points over.

If you have a float arm, can you find someone in your area with a refract to tell you how it is reading ?

 

[Kevin1000]

Take a water sample to the lfs and have it tested.

 

[kim]

That looks like too big a change for 5 C temperature difference. Anyway, unless you know (a) at what temperature your hydrometer was calibrated (the "calibration temperature") and (b) what definition of SG it uses (the "reference temperature"), it's useless.

There's nothing wrong with a decent hydrometer - they will have this information inscribed on the body.

kim

 

[J.Howard]

For my swinger I use this site to get corrected measurments for temp. It even does the math for you. Many other cool calcs. there as well:
http://www.aquasite.com/knowledge/calculator/specific_gravity.shtml